This analytic investigation shows how the electromagnetic wave energy conversion (EWEC) device, as used for solar-to-electric power conversion, is significantly different from solar cells, with respect to principles of operation. An optimistic estimate of efficiency is about 80% for a full-wave rectifying configuration with solar radiation normally incident. This compares favorably with the theoretical maximum for a CdTe solar cell (23.5%), as well as with the efficiencies of more familiar cells: Si (19.5%), InP (21.5%), and GaAs (23%). Some key technological issues that must be resolved before the EWEC device can be realized are identified. Those issues include: the fabrication of a pn semi-conductor junction with no permittivity resonances in the optical band; and the efficient channeling of the power received by countless microscopic horn antennas through a relatively few number of wires.